Henstridge has now boarded the project to play S.H.I.E.L.D. science expert Gemma Simmons, according to The Hollywood Reporter.

De Caestecker - who previously appeared in the UK's Coronation Street and The Fades - has also signed on for ABC's Marvel series as Agent Leo Fitz, the strategic intelligence group's technology specialist.

The pilot for S.H.I.E.L.D. is being written by Avengers director Joss Whedon with his brother Jed Whedon and Drop Dead Diva's Maurissa Tancharoen.

S.H.I.E.L.D. will be set in the Marvel cinematic universe, but is to focus on stories specifically revolving around Nick Fury's security force.